Pediatric Anesthesia: Dosage & Considerations

• Local anesthesia helps alleviate anxiety and discomfort in pediatric patients during restorative and surgical procedures
• Good operator technique and mastery of key areas are essential for pediatric local anesthesia

Areas of Mastery Needed:

• Child growth and development (physical and mental)
• Behavior management
• Sound technique
• Pharmacology of local anesthetics
• Thorough preoperative medical evaluation including medical history, weight, BMI, adverse drug interactions, and medical consults is required before anesthetic administration

General Considerations for ADHD

• Many children get prescriptions for ADHD medications like Ritalin (methylphenidate) and other amphetamines
• Limit epinephrine dosage to 0.04mg in children with ADHD
• 1:100 000 Epi contains 0.01mg/ml

General Considerations Overview

• Patient weight
• Type and extent of the procedure
• Tissue at the injection site
• Patient cooperation

Local Anesthetic Properties: Potency

• Intrinsic potency is the concentration needed for nerve blockade
• Lidocaine, prilocaine, mepivacaine, and articaine have intermediate potency
• Bupivacaine has the highest potency
• Efficacy depends on concentration at nerve segment; excess is wasteful and dangerous
• Failure to obtain the necessary anesthesia is most likely due to Operator error when depositing the solution sufficiently close to the desired nerve
• Anatomic aberrations can also cause issues (accessory innervation)
• Local anesthetics do not necessarily come in the same concentration
• Exercise caution to prevent exceeding toxic doses, especially with cardiovascular or sedative agents
• 4% articaine concentration requires special care with children, amount is twice of 2% solution

Duration

• Duration of anesthesia is a key consideration when determining the correct agent and procedure and is best predicted based on protein-binding characteristics
• Adding a vasoconstrictor will slow absorption and update into the bloodstream away from the injection site
• Duration varies with the regional technique and anesthetic agent used
• Local anesthetic duration matters when assessing possible post operative problems like trauma
• Young children are more likely to experience soft tissue injury from prolonged effects, which needs consideration when picking duration and determining the procedure

Dosage

• Effective local anesthetic blocks require adequate concentration and volume, dosage constrained by toxicity risks
• For a 20kg child using 2% Lidocaine 1:100 000 Epi
• 20kg*4.4 mg/kg = 88mg max allowable lidocaine
• 88mg/36 mg/ carpule = Approximately 2.44 carpules that can be used

Vasoconstrictors

• Vasoconstrictor agents like epinephrine affect onset time, duration, and quality of block
• Vasoconstrictors decrease the rate of systemic drug absorption by constricting blood vessels which reduces local blood flow, which counters the vasodilatory effects of the local anesthetic while maintaining a higher anesthetic concentration where injected
• Adding a vasoconstrictor prolongs the duration of local anesthesia
• Vasoconstrictors reduce toxic effects of local anesthetics because absorption into systemic circulation is delayed

Toxicity

• Local anesthetics are common in dentistry so the potential for toxicity can be easily overlooked
• Children possess higher cardiac output, a higher basal metabolic rate, and a higher tissue perfusion degree than adults
• Local anesthetic drugs tend to be absorbed more rapidly from those tissues in children
• Always calculate the maximal safe dose of local anesthetic for each patient, and never exceed those limits

Central Nervous System Reactions

• Initial CNS excitation includes circumoral numbness, dizziness, tinnitus, difficulty focusing the eyes
• Excitation is followed by CNS depression, shown as drowsiness, sedation, loss of consciousness (slurred speech, shivering, seizure activity)

Cardiovascular System Reactions

• HR and BP increase during CNS stimulation periods
• Bradycardia and lowered BP occur during CNS depression

Topical Anesthesia

• Topical anesthesia is for obtunding discomfort when inserting needles into the mucosal membrane

Disadvantages

-Taste of topical anesthetic -The period during which the patient anticipates the needle -The establishment of a conditioned patient response from the needle immediately following the application of topical anesthetic

• Operator's effectiveness by interacting with children supersedes those disadvantages

Benzocaine

• Benzocaine topical gel is recommended as easy-to-control
• Best results behaviorally and physiologically when gel is used sparingly
• Apply to a dry mucosal surface for at least 2 minutes

Formulations

• Multiple formulations and flavours are available
• 20% Benzocaine is most common
• You can get compounded formulations from a pharmacy, for example: Lidocaine + Tetracaine + Phenylephrine

Technique

• Apply a small amount of topical anesthetic with a cotton-tipped applicator; dry and isolate mucosa with a 2-by 2-inch cotton gauze
• Apply for 2 minutes
• Effective for surface tissues up to 3mm in depth when appropriately applied
• Allows for atraumatic needle penetration of the mucous membrane

Complications

• Allergic reactions to benzocaine ester anesthetics, can potentially occur
• 1 in 7000 exposures to benzocaine may result in methemoglobinemia.
• This results in nonfunctional hemoglobin that is unable to complete oxygen binding, which is a cause of hypoxemia
• Minimum clinically effective dose imperative for clinicians to use when using benzocaine
• Clinicians should discuss those risks with parents regarding over-the-counter benzocaine purchasing for home use during teething discomfort

Needle Selection

• Needle gauge should be determined by the injection required
• Use a Short (20mm) or Long (32mm), between 27-30 gauge needle for most intraoral injections in children, consisting of mandibular blocks
• Little discomfort difference among 25, 27, or 30 gauge needles with inferior alveolar injections
• 27 gauge needle is less likely to break or bend during injections compared to 30 gauge
• Extra-short 30 gauge can be good with maxillary anterior injections.

Injection Technique

• Communication at an appropriate development level is very important!
• A dentist should not deny possible injection hurt, this denial may cause the child to lose trust and confidence surrounding the procedure
• Reinforce comfort but do not instill unneeded anxieties and fears about the "pinch"
• Discomfort is lessensed by counter-stimulation, distraction, and slow administration rate
• Assistants have an important role in how local anesthetic is applied
• Reflexive movements of the child's head and body should be anticipated
• Passive arm extension across the child's chest allows them to intercept body and arm movements
• Head is stabilized by holding firmly but gently between body and arm of dentist
• After needle penetrates tissue it cannot be retracted

Maxillary Anesthesia

• Innervation of primary and permanent molars arises from the posterosuperior alveolar nerve (permanent molars) and middle superior alveolar nerve (mesiobuccal root of the first permanent molar, primary molars, and premolars)
• Superperiosteal injection is indicated
• Penetrate the mucobuccal fold at a depth approximating the buccal roots of the tooth
• Innervation of primary and permanent incisors and canines goes to the anterosuperior alveolar branch of the maxillary nerve
• Use labial infiltration
• Rapid deposition is contraindicated, it produces discomfort during rapid expansion of tissue
• Tissues of hard palate are innervated via the anterior palatine and nasal palatine nerves. The nasal palatine nerve block and anterior palatine anesthesia is generally not needed with normal restorative procedures
• A small amount of anesthetic should be deposited near the marginal tissue of the tooth’s lingual aspect
• Apply topical anesthesia
• Use pressure anesthesia with a cotton applicator

Mandibular Tooth Anesthesia

• The IAN innervates mandibular primary and permanent teeth, the nerve enters the mandibular foramen on the mandibular lingual aspect
• The foramen is approximately midway between the anterior and posterior borders of the ramus of the mandible
• The foramen gradually remodels as the child matures from the occlusal plane into adulthood
• The foramen is at or slightly above this occlusal plane with primary dentition
• In adulthood it would be at an average of 7mm above occlusal plane

Technique for IAN Block

• The child needs to open their mouth as wide as they possibly can
• Insert the needle between the internal oblique ridge and the pterygomandibular raphe
• The barrel of the syringe overlies the two primary mandibular molars on the opposite side of the arch, and parallels the occlusal plane
• Advance the needle until contact with the bone is made
• Attempt additional tries if the IAN block does not succeed, inserting the needle above the first injection site

Infiltration

• Local infiltration in the mandibular buccal vestibule adjacent to teeth has been advocated to diminish soft tissue anesthesia and possible soft tissue injury associated with the IAN
• This should be considered with young children in the primary, or early mixed dentition phase
• A small amount is required for the level of the tooth roots
• Provides easy administration, saves language and lips from profound anesthesia
• Use "rule of 10": tooth number + age less than or equal to 10 (Dr. Avram)

Complications of Local Anesthesia

• Local complications: masticatory trauma, hematomas, infections, nerve damage by the needle, trismus, and needle breakage
• Minimize such complications, and lower deflection
• Warn parent and child that tissue will be anesthetized for about 1-2 hours after the restorative procedure

Preventing Post Op Trauma

• Choose local anesthetic given a planned procedure duration; should not last much longer or shorter than required
• Advise patient and adults of potential issues from sucking, chewing, or biting lip, teeth, or cheek
• Manage soft tissue traumas by reassuring patient/parent, and if tissue changes color, lubricate the area with petroleum jelly or antibiotic ointment to avoid cracking/drying for roughly a week

Explore pediatric anesthesia considerations for dental procedures. Learn about epinephrine dosage limits for children with ADHD, factors influencing local anesthetic selection, and reasons for anesthesia failure in pediatric patients. Understand the importance of profound anesthesia and safety precautions.